/*
 * 全选
 */
function selectAll(chkName)
{
	for(var i=0;i<document.getElementsByName(chkName).length;i++)
	{
		if(!document.getElementsByName(chkName)[i].checked)
		{
			document.getElementsByName(chkName)[i].checked=true;
		}
	}
}
/*
 * 取消全选
 */
function cancelAll(chkName)
{
	for(var i=0;i<document.getElementsByName(chkName).length;i++)
	{
		if(document.getElementsByName(chkName)[i].checked)
		{
			document.getElementsByName(chkName)[i].checked=false;
		}
	}
}